objects-inl.h.svn-base

Google浏览器V8内核代码

// Copyright 2006-2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Review notes:
//
// - The use of macros in these inline fuctions may seem superfluous
// but it is absolutely needed to make sure gcc generates optimal
// code. gcc is not happy when attempting to inline too deep.
//

#ifndef V8_OBJECTS_INL_H_
#define V8_OBJECTS_INL_H_

#include "objects.h"
#include "contexts.h"
#include "conversions-inl.h"
#include "property.h"

namespace v8 { namespace internal {

PropertyDetails::PropertyDetails(Smi* smi) {
  value_ = smi->value();
}


Smi* PropertyDetails::AsSmi() {
  return Smi::FromInt(value_);
}


#define CAST_ACCESSOR(type)                     \
  type* type::cast(Object* object) {            \
    ASSERT(object->Is##type());                 \
    return reinterpret_cast<type*>(object);     \
  }


#define INT_ACCESSORS(holder, name, offset)                             \
  int holder::name() { return READ_INT_FIELD(this, offset); }           \
  void holder::set_##name(int value) { WRITE_INT_FIELD(this, offset, value); }


#define ACCESSORS(holder, name, type, offset)                           \
  type* holder::name() { return type::cast(READ_FIELD(this, offset)); } \
  void holder::set_##name(type* value) {                                \
    WRITE_FIELD(this, offset, value);                                   \
    WRITE_BARRIER(this, offset);                                        \
  }


#define SMI_ACCESSORS(holder, name, offset)             \
  int holder::name() {                                  \
    Object* value = READ_FIELD(this, offset);           \
    return Smi::cast(value)->value();                   \
  }                                                     \
  void holder::set_##name(int value) {                  \
    WRITE_FIELD(this, offset, Smi::FromInt(value));     \
  }


#define BOOL_ACCESSORS(holder, field, name, offset) \
  bool holder::name() {                                    \
    return BooleanBit::get(field(), offset);               \
  }                                                        \
  void holder::set_##name(bool value) {                    \
    set_##field(BooleanBit::set(field(), offset, value));  \
  }


bool Object::IsSmi() {
  return HAS_SMI_TAG(this);
}


bool Object::IsHeapObject() {
  return HAS_HEAP_OBJECT_TAG(this);
}


bool Object::IsHeapNumber() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map()->instance_type() == HEAP_NUMBER_TYPE;
}


bool Object::IsString() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map()->instance_type() < FIRST_NONSTRING_TYPE;
}


bool Object::IsSeqString() {
  return IsString()
    && (String::cast(this)->representation_tag() == kSeqStringTag);
}


bool Object::IsAsciiString() {
  return IsString() && (String::cast(this)->is_ascii());
}


bool Object::IsTwoByteString() {
  return IsString() && (!String::cast(this)->is_ascii());
}


bool Object::IsConsString() {
  return IsString()
    && (String::cast(this)->representation_tag() == kConsStringTag);
}


bool Object::IsSlicedString() {
  return IsString()
    && (String::cast(this)->representation_tag() == kSlicedStringTag);
}


bool Object::IsExternalString() {
  return IsString()
    && (String::cast(this)->representation_tag() == kExternalStringTag);
}


bool Object::IsExternalAsciiString() {
  return IsExternalString() && (String::cast(this)->is_ascii());
}


bool Object::IsExternalTwoByteString() {
  return IsExternalString() && (!String::cast(this)->is_ascii());
}


bool Object::IsShortString() {
  return IsString() && (String::cast(this)->size_tag() == kShortStringTag);
}


bool Object::IsMediumString() {
  return IsString() && (String::cast(this)->size_tag() == kMediumStringTag);
}


bool Object::IsLongString() {
  return IsString() && (String::cast(this)->size_tag() == kLongStringTag);
}


bool Object::IsSymbol() {
  return IsString() && (String::cast(this)->is_symbol());
}


bool Object::IsNumber() {
  return IsSmi() || IsHeapNumber();
}


bool Object::IsByteArray() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map()->instance_type() == BYTE_ARRAY_TYPE;
}


bool Object::IsFailure() {
  return HAS_FAILURE_TAG(this);
}


bool Object::IsRetryAfterGC() {
  return HAS_FAILURE_TAG(this)
    && Failure::cast(this)->type() == Failure::RETRY_AFTER_GC;
}


bool Object::IsException() {
  return this == Failure::Exception();
}


bool Object::IsJSObject() {
  return IsHeapObject()
    && HeapObject::cast(this)->map()->instance_type() >= FIRST_JS_OBJECT_TYPE;
}


bool Object::IsMap() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map()->instance_type() == MAP_TYPE;
}


bool Object::IsFixedArray() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map()->instance_type() == FIXED_ARRAY_TYPE;
}


bool Object::IsDescriptorArray() {
  return IsFixedArray();
}


bool Object::IsContext() {
  return Object::IsHeapObject()
    && (HeapObject::cast(this)->map() == Heap::context_map() ||
        HeapObject::cast(this)->map() == Heap::global_context_map());
}


bool Object::IsGlobalContext() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map() == Heap::global_context_map();
}


bool Object::IsJSFunction() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map()->instance_type() == JS_FUNCTION_TYPE;
}


template <> inline bool Is<JSFunction>(Object* obj) {
  return obj->IsJSFunction();
}


bool Object::IsCode() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map()->instance_type() == CODE_TYPE;
}


bool Object::IsOddball() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map()->instance_type() == ODDBALL_TYPE;
}


bool Object::IsSharedFunctionInfo() {
  return Object::IsHeapObject() &&
      (HeapObject::cast(this)->map()->instance_type() ==
       SHARED_FUNCTION_INFO_TYPE);
}


bool Object::IsJSValue() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map()->instance_type() == JS_VALUE_TYPE;
}


bool Object::IsProxy() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map()->instance_type() == PROXY_TYPE;
}


bool Object::IsBoolean() {
  return IsTrue() || IsFalse();
}


bool Object::IsJSArray() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map()->instance_type() == JS_ARRAY_TYPE;
}


bool Object::IsJSRegExp() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map()->instance_type() == JS_REGEXP_TYPE;
}


template <> inline bool Is<JSArray>(Object* obj) {
  return obj->IsJSArray();
}


bool Object::IsHashTable() {
  return Object::IsHeapObject()
    && HeapObject::cast(this)->map() == Heap::hash_table_map();
}


bool Object::IsDictionary() {
  return IsHashTable() && this != Heap::symbol_table();
}


bool Object::IsSymbolTable() {
  return IsHashTable() && this == Heap::symbol_table();
}


bool Object::IsCompilationCacheTable() {
  return IsHashTable();
}


bool Object::IsMapCache() {
  return IsHashTable();
}


bool Object::IsPrimitive() {
  return IsOddball() || IsNumber() || IsString();
}


bool Object::IsGlobalObject() {
  return IsHeapObject() &&
      ((HeapObject::cast(this)->map()->instance_type() ==
        JS_GLOBAL_OBJECT_TYPE) ||
       (HeapObject::cast(this)->map()->instance_type() ==
        JS_BUILTINS_OBJECT_TYPE));
}


bool Object::IsJSGlobalObject() {
#ifdef DEBUG
  if (IsHeapObject() &&
      (HeapObject::cast(this)->map()->instance_type() ==
       JS_GLOBAL_OBJECT_TYPE)) {
    ASSERT(IsAccessCheckNeeded());
  }
#endif
  return IsHeapObject() &&
      (HeapObject::cast(this)->map()->instance_type() ==
       JS_GLOBAL_OBJECT_TYPE);
}


bool Object::IsJSBuiltinsObject() {
  return IsHeapObject() &&
      (HeapObject::cast(this)->map()->instance_type() ==
       JS_BUILTINS_OBJECT_TYPE);
}


bool Object::IsUndetectableObject() {
  return IsHeapObject()
    && HeapObject::cast(this)->map()->is_undetectable();
}


bool Object::IsAccessCheckNeeded() {
  return IsHeapObject()
    && HeapObject::cast(this)->map()->needs_access_check();
}


bool Object::IsStruct() {
  if (!IsHeapObject()) return false;
  switch (HeapObject::cast(this)->map()->instance_type()) {
#define MAKE_STRUCT_CASE(NAME, Name, name) case NAME##_TYPE: return true;
  STRUCT_LIST(MAKE_STRUCT_CASE)
#undef MAKE_STRUCT_CASE
    default: return false;
  }
}


#define MAKE_STRUCT_PREDICATE(NAME, Name, name)                  \
  bool Object::Is##Name() {                                      \
    return Object::IsHeapObject()                                \
      && HeapObject::cast(this)->map()->instance_type() == NAME##_TYPE; \
  }
  STRUCT_LIST(MAKE_STRUCT_PREDICATE)
#undef MAKE_STRUCT_PREDICATE


bool Object::IsUndefined() {
  return this == Heap::undefined_value();
}


bool Object::IsTheHole() {
  return this == Heap::the_hole_value();
}


bool Object::IsNull() {
  return this == Heap::null_value();
}


bool Object::IsTrue() {
  return this == Heap::true_value();
}


bool Object::IsFalse() {
  return this == Heap::false_value();
}


double Object::Number() {
  ASSERT(IsNumber());
  return IsSmi()
    ? static_cast<double>(reinterpret_cast<Smi*>(this)->value())
    : reinterpret_cast<HeapNumber*>(this)->value();
}



Object* Object::ToSmi() {
  if (IsSmi()) return this;
  if (IsHeapNumber()) {
    double value = HeapNumber::cast(this)->value();
    int int_value = FastD2I(value);
    if (value == FastI2D(int_value) && Smi::IsValid(int_value)) {
      return Smi::FromInt(int_value);
    }
  }
  return Failure::Exception();
}


Object* Object::GetElement(uint32_t index) {
  return GetElementWithReceiver(this, index);
}


Object* Object::GetProperty(String* key) {
  PropertyAttributes attributes;
  return GetPropertyWithReceiver(this, key, &attributes);
}


Object* Object::GetProperty(String* key, PropertyAttributes* attributes) {
  return GetPropertyWithReceiver(this, key, attributes);
}


#define FIELD_ADDR(p, offset) \
  (reinterpret_cast<byte*>(p) + offset - kHeapObjectTag)

#define READ_FIELD(p, offset) \
  (*reinterpret_cast<Object**>(FIELD_ADDR(p, offset)))

#define WRITE_FIELD(p, offset, value) \
  (*reinterpret_cast<Object**>(FIELD_ADDR(p, offset)) = value)

#define WRITE_BARRIER(object, offset) \
  Heap::RecordWrite(object->address(), offset);

#define READ_DOUBLE_FIELD(p, offset) \
  (*reinterpret_cast<double*>(FIELD_ADDR(p, offset)))

#define WRITE_DOUBLE_FIELD(p, offset, value) \
  (*reinterpret_cast<double*>(FIELD_ADDR(p, offset)) = value)

#define READ_INT_FIELD(p, offset) \
  (*reinterpret_cast<int*>(FIELD_ADDR(p, offset)))

#define WRITE_INT_FIELD(p, offset, value) \
  (*reinterpret_cast<int*>(FIELD_ADDR(p, offset)) = value)

#define READ_SHORT_FIELD(p, offset) \
  (*reinterpret_cast<uint16_t*>(FIELD_ADDR(p, offset)))

#define WRITE_SHORT_FIELD(p, offset, value) \
  (*reinterpret_cast<uint16_t*>(FIELD_ADDR(p, offset)) = value)

#define READ_BYTE_FIELD(p, offset) \
  (*reinterpret_cast<byte*>(FIELD_ADDR(p, offset)))

#define WRITE_BYTE_FIELD(p, offset, value) \
  (*reinterpret_cast<byte*>(FIELD_ADDR(p, offset)) = value)


Object* HeapObject::GetHeapObjectField(HeapObject* obj, int index) {
  return READ_FIELD(obj, HeapObject::kHeaderSize + kPointerSize * index);
}


int Smi::value() {
  return reinterpret_cast<int>(this) >> kSmiTagSize;
}


Smi* Smi::FromInt(int value) {
  ASSERT(Smi::IsValid(value));
  return reinterpret_cast<Smi*>((value << kSmiTagSize) | kSmiTag);
}


Failure::Type Failure::type() const {
  return static_cast<Type>(value() & kFailureTypeTagMask);
}


bool Failure::IsInternalError() const {
  return type() == INTERNAL_ERROR;
}


bool Failure::IsOutOfMemoryException() const {
  return type() == OUT_OF_MEMORY_EXCEPTION;
}


int Failure::requested() const {
  const int kShiftBits =
      kFailureTypeTagSize + kSpaceTagSize - kObjectAlignmentBits;
  STATIC_ASSERT(kShiftBits >= 0);
  ASSERT(type() == RETRY_AFTER_GC);
  return value() >> kShiftBits;
}


AllocationSpace Failure::allocation_space() const {
  ASSERT_EQ(RETRY_AFTER_GC, type());
  return static_cast<AllocationSpace>((value() >> kFailureTypeTagSize)
                                      & kSpaceTagMask);
}